问题补充:
20. , English is one of the most important subjects.
A. It is known to all that
B. As is known to all that
C. As we know
D. As it is known to all
答案:
A. It is known to all that
B. As is known to all that
(答案→)C. As we know
D. As it is known to all
解析:可联系答.案.网客服索取。